内 容 提 要
形容词和副词在语法结构中主要用于比较级和最高级。形容词和副词的构成形式基本上一样，它们的形式与单音节、双音节和多音节有关，当然还有其特殊形式。形容词和副词比较级的基本用法分为同级比较、比较级和最高级三种形式。但这三种形式都有它们特殊的表达方式以及它们的惯用法。对以下要点大家须一一掌握。
I形容词比较级和最高级的形式
一、形容词比较级和最高级的构成
形容词的比较级和最高级变化形式规则如下
构 成 法 原 级 比 较 级 最 高 级
① 一般单音节词末尾加瞖r 和 瞖st strong stronger strongest
② 单音节词如果以瞖结尾，只加瞨 和瞫t strange stranger strangest
③ 闭音节单音节词如末尾只有 一个辅音字母，
须先双写这个辅音字母，再加瞖r和瞖st sad
big
hot sadder
bigger
hotter saddest
biggest
hottest
④ 少数以瞴,瞖r(或瞮re),瞣w,瞓le结尾的双音节词， 末尾加瞖r和瞖st(以瞴结尾的词，如瞴前是辅音字母， 把y变成i，再加瞖r和瞖st，以瞖结尾的词仍加瞨和瞫t) angry
clever
narrow
noble angrier
cleverer
narrower
nobler angrest
cleverest
narrowest
noblest
⑤ 其他双音节和多音节词都在前面加单词more和most different more
different most
different
1) The most high ［A］ mountain in ［B］ the world is Mount Everest， which is situated ［C］ in Nepal and is twenty瞡ine thousand one hundred and fourty one feet high ［D］ .
2) This house is spaciouser ［A］ than that ［B］ white ［C］ one I bought in Rapid City， South Dakota ［D］ last year.
3) Research in the social ［A］ sciences often proves difficulter ［B］ than similar ［C］ work in the physical ［D］ sciences.
二、形容词比较级或最高级的特殊形式：
1. 三个或三个以上音节的形容词只能加more和most
只能说 more beautiful而不能说beautifuller; 只能说the most beautiful而不能说beautifullest。
但是，以形容前缀瞮n结尾的三音节形容词不适合上述情况，如unhappy,untidy，我们可以说：unhappier→unhappiest, untidier→untidiest
2. 由睮NG分词和睧D分词演变过来的形容词(包括不规则动词如know→known)只能加more或most来表示它们的比较级和最高级
more(most) striking, more(most) interesting, more(most) wounded, more(most)worn等。
4) The drawings ［A］ of the old masters ［B］ are among the treasuredest ［C］ works in museums ［D］ .
3. 英语里有些形容词由于其词义而不可能有比较级形式
absolute fatal main right universal
chief final naked simulta- utter
entire foremost perfect neous vital
eternal inevitable possible sufficient whole
excellent infinite primary supreme wooden
三、不规则形容词的比较级和最高级形式
good well better best
bad ill worse worst
many much more most
little few less least
far farther farthest
further furthest
5) African elephants are larger， fiercer， and difficulter ［A］ to tame ［B］ than ［C］ Asian elephants ［D］ .
6) Sarah Hale became ［A］ one of the famousest ［B］ magazine ［C］ editors in the United States during ［D］ the 1800’s.
7) Of all ［A］ the Native American tribes ［B］ ， the Shawnee Indians were ［C］ a most ［D］ transient.
四、例题解析
1) A错。应将“most high”改为highest。这是在考形容词比较级的构成形式。
2) A错。改为more spacious。
3) B错。 改为more difficult。
4) C错。 treasured 在本句中是睧D分词(动词treasure ＋ed)作形容词使用，是“宝贵的、珍贵的”意思，修饰名词 works(作品)，其最高级形式应用 the most treasured。
5) A错，改为more difficult。
6) B错。改为“the most famous”，因为famous(著名的)是双音节，其最高级变化应在前面加“the most”。
7) D错。应改为“the most”，因为此处表示的是最高级，“the most transient”意为“(延续时间)最短暂的”。
II 副词比较级和最高级的形式
副词比较级和最高级的变化形式与形容词基本上一样
一般 副词
hard→harder →hardest
fast→faster →fastest
late→later →latest
early→earlier →earliest
特殊 副词
well →better →best
much →more →most
badly →worse →worst
little →less →least
但是，开放类副词即以后缀瞝y结尾的副词不能像形容词那样加瞖r或瞖st，如
quickly →more quickly →most quickly quietly →more quietly →most quietly
［注］： early中的瞝y不是后缀，故可以把瞴变瞚再加瞖r和瞖st
III形容词与副词比较级和最高级的基本用法
一、原级比较的基本用法
1. 原级比较由“as＋形容词或副词(或再加名词或短语)＋as ”构成“原级相同”比较句，表示两者比较；其否定式，即“程度不及”比较句型为“not so(as) ＋形容词或副词＋as”，而且as…as结构前可用just, almost, nearly, quite等表示程度的词修饰
1) Walking briskly for thirty minutes will burn as many calories as .
［A］ to run for fifteen minutes
［B］ running for fifteen minutes
［C］ you run for fifteen minutes
［D］ fifteen瞞inute walking
2) The gorilla(大猩猩)， while ［A］ not quite as curious than ［B］ the chimpanzee(黑猩猩)， shows more persistence ［C］ and memory retention(记忆力) in solving ［D］ a problem.
3) Alaska is twice ［A］ as larger ［B］ as ［C］ the next largest ［D］ state， Texas.
2. “as (so)＋名词＋as＋名词”进行名词比较，这时一般情况下有一个表示原级的比较词，但如果第一名词前出现了形容词修饰该词或出现副词修饰谓语，应当用so而不用as
4) Thomas Jefferson’s achievements as an architect rival his contributions a politician.
［A］ such
［B］ more
［C］ as
［D］ than
5) I should say Henry is not much a writer as a reporter. (88年考题)
［A］ that
［B］ so
［C］ this
［D］ as
二、比较级
1. 比较级由“形容词(副词)比较级＋than＋…，”构成表示在两者中间一方比另一方“更加…”。连词than后可接句子，也可接名词、代词、名词短语、介词短语、动词、动词不定式、睮NG结构和睧D结构，有时也可省去than。
6) Natural mica(云母) of ［A］ a superior ［B］ quality is cheapest ［C］ to obtain than synthetic ［D］ mica.
7) She is older than .
［A］ any other girl in the group
［B］ any girl in the group
［C］ all girls in the group
［D］ you and me as well as the group
8) Josephine McCrackin joined ［A］ the “Santa Cruz Sentinel” in 1905 and， until her death fifteen years late ［B］ ， remained ［C］ active in journalistic ［D］ work.
2. 注意than前后两项相比较的人或事物要一致
9) The purpose of the research had a more important meaning for them than .
［A］ ours
［B］ with us
［C］ for ours it had
［D］ it did for us
10) Sound travels air.
［A］ faster through water than through
［B］ faster than through water and
［C］ through water faster and
［D］ where it is faster through water than through
11) Gerbrand von den Feckhout， one of Rembrand’s pupils， followed ［A］ the style of his teacher so implicitly that ［B］ his paintings ［C］ are sometimes confused with his master ［D］ .
三、最高级
1. 最高级用于三者以上比较，形容词的结构形式是“定冠词＋形容词最高级＋名词＋表示范围的短语或从句”(如all, of all, of the tree, in the world, that has ever taken place等)
12) The more ［A］ fearsome of all the ［B］ animals in ［C］ the Western ［D］ Hemisphere is the grizzly bear.
13) Of all economic ［A］ problems， inflation continues to be ［B］ a ［C］ most significant in its daily impact on ［D］ people and business.
14) ， the most familiar to general public is the criminal jurisdiction.
［A］ All the activities
［B］ The activities
［C］ Of all the activities
［D］ It is the activities
2. 副词的最高级与形容词最高级的区别在于最高级前没有定冠词the
四、例题解析
1) B为正确答案。
2) B错。改为 as ，和前面的as和形容词原形curious 一起构成同程度比较。
3) B错。 改为as large。
4) C对。动词rival(胜过、匹敌)前后是两个相比较的成分achievements(成果)和 contributions(贡献)，由于前面的名词后出现了短语 as an architect，故空白处也应用as，使前后对比成分一致。
5) B为正确答案。
6) C错。应改为比较级cheaper。比较级后并不一定跟接连词than，有时在其间有名词或名词短语(被形容词所修饰)，介词短语，不定式或其他成分隔开。
7) A为正确答案。“She”作为单个不能跟全组比(C和D不对)，也不能跟全组所有相比，因为“她”也是其中一员，自然“她”不能跟自己相比。这里“She”比较的是“这组中的任何一个”，所以A对。
8) B错。应改为比较级later，因此处实为与1905年相比晚15年，故应使用比较级。
9) D为正确答案。
10) A为正确答案。
11) D错。 改为his master’s。
12) A错。 改为most。
13) C错。改为the， significant是多音节形容词，在此处应用最高级形式(在前面加 the most)，注意句中的“of all… ”。
14) C为正确答案。本句空白处缺状语，A和B全为名词短语，不符合条件；D为句子，和空白后面的句子没有任何联系，故亦应排除。只有C正确，和后面的最高级the most familiar前后呼应。
IV 形容词和副词的特殊表达法
一、形容词与副词的同级比较： 由“as(so)…as”引出，其否定式为“not so…”或“not as…as”,考生还应注意下列含有“as”结构或短语的句子
1. as such：表示上文所指明的事或人
He is a child,and must be treated as such. 他是个孩子，必须被当作孩子对待。
2. as much：表示“与…同量”
Take as much as you like. 拿多少都行。
I would gladly have paid twice as much for it. 就是价格再贵一倍，我也会愿意把它买下的。
He as much as admitted the whole story. 他几乎全部承认了。
3. as many：表示“与…一样多”
I found six mistakes in as many lines. 我在六行中发现了六个错。
二、表示“几倍于”的比较级：用twice (两倍)，four times (四倍)，ten times (十倍)加上as … as 结构
This one is four times as big as that one. 这个是那个的四倍大。(这个比那个大三倍。) / Our campus is three times as large as yours. 我们的校园比你们的大两倍。 / He has books twice as many as she does. 他的书比她多一倍。
1) The five瞴ear deal obligates ［A］ the country to buy nine million tons ［B］ of grain a year ［C］ ， three million more as ［D］ the old pact’s minimum.
三、“the same ＋名词＋as”表示同等比较
2) The lens of a camera performs the lens of the eye.
［A］ in the same function
［B］ the same function as
［C］ the function is the same as
［D］ and has the same function
3) The elimination of inflation would ensure that the amount of money used in repaying a loan would have as the amount of money borrowed.
［A］ as the same value
［B］ the same value
［C］ value as the same
［D］ the value is the same
四、比较级前可用a little, a bit, slightly, a great deal, a lot,many, much等词语表示不定量，far, completely,still表示程度或更进一步
4) There are now methods for studying color vision in infants than there once were.
［A］ more sophisticated than
［B］ much more sophisticated
［C］ much sophisticated
［D］ sophisticated
5) The photographs of Mars taken by satellite are than those taken from the Earth.
［A］ clearest
［B］ the clearest
［C］ much clearer
［D］ more clearer
6) Common porpoises(海豚) are usually not considered ［A］ migratory， although ［B］ some do move ［C］ to more warmer ［D］ waters in winter.
五、与比较级有关的特殊词用法
1. no more than …表示“只不过”，“并不比…”(等于not any more than)
7) During observations made over a fifty瞴ear period， the power output of the Sun has than a few tenths of one percent.
［A］ varied by no more
［B］ varied no more by
［C］ not varied more by
［D］ more varied by not
Man cannot live without food any more than plants can grow without sunshine. 人没有食物不能生存，植物没有阳光也不能生长。
There is no difficulty with this task any more than with that one. 这项任务没有困难，那项任务也没有困难。
2. no less than 表示“不亚于”
There are no less than five hundred people present at the New Year party.
出席新年晚会的有五百人之多。(出席的人较多)
3. not less than 表示“不少于”
There are not less than five hundred people present at the New Year party.
出席新年晚会的只有五百人。(出席的人较不多)
4. more often than not 表示“多数情况下”
On Friday mornings, he comes late more often than not.
多数情况下，他星期五来得晚。
5. all the more 因而更加
We really admired him all the more for his frankness. 我们更加钦佩他的坦率。
6. (be) better off 较富裕，环境较好
8) Few of the people who live on the cooperatives than they were as laborers.
［A］ is well off financial
［B］ financially well off
［C］ are better off finanically
［D］ financial better off
7. had better 最好……
Come, you had much better have the thing out at once. 来，你最好把这东西弄出去。
8. less than 不到
The first steam locomotive could have a top speed of only thirteen mph(miles per hour) and the great sailing ships of the time labored along at less than half that speed.第一列蒸汽火车最快每小时只有13英里，那时的大船还不到这个速度的一半。
9. little more than 差不多
The grain in their barn is little more than that of ours. 他们仓的粮食跟我们仓的粮食差不多。
10. more than 超过，不止
I have waited for your for more than two hours. 我等了你两个多小时。
11. more or less 大体上，或多或少
The work is more or less finished. 工作大体算完成了。
Most of them came here to near money, more or less Mr.Wang worked for his cause.他们大都来挣钱的，但王先生有点像为事业而工作。
12. other than除了
They imposed no pre瞔onditions other than that the meeting should be held in their capital. 除了会议要在他们的首都开之外，他们没有提出任何先决条件。
13. rather than 而不是，与其…宁愿(rather than表示“与其…宁愿”时，如果位于句首引导句子，有虚拟的成分，相当于“… would rathe than，”所以rather than后面跟动词原形)
Read what interests you; read what you have time for magazines and newspapers rather than novels.
读你感兴趣的东西，读你有时间读的东西，如杂志和报纸而不是小说。
Rather than allow the potatoes to go bad, she sold them at half price. 她以半价把土豆给卖了，而没有让它们烂掉。
Rather than cause trouble, he left. 为了不惹事，他还是走了。
9) He came all the way to China for promoting friendship for making money.
［A］ other than
［B］ better than
［C］ more than
［D］ rather than
10) He preferred to write the letter by hand .
［A］ to typing it
［B］ than type it
［C］ to type it
［D］ rather than type it
14. so much the better 就更好了
If she will help us, so much the better. 如果他能帮我们，那就更好了。
15. so much the worse 就更糟了
So much the worse for you if you still are absent from class. 如果你继续逃课的话，就对你更不利了。
16. the more…the more(less)“越是……，就越……”
11) The harder he tried， ［A］ the worst ［B］ he danced ［C］ before the large ［D］ audience.
12) The quicker a loan ［A］ is repaid ［B］ ， the least ［C］ it will ［D］ cost.
六、比较中的省略
1. 在as…as中，as从句可省略整个谓语部分，保留主语
She sings as well as her sister. 她跟她的姐姐唱得一样好(省去了does)。
2. 可以省去谓语部分，保留主语和be、have等助动词
Susan has done as much housework as you have. (省去了done。)
3. 可以省去主语和谓语，只剩下状语
It is not as cold in Beijing as in Datong. 北京的天气没有大同冷。
4. than从句也可以省去整个谓语部分，保留主语
They say that blood is thicker than water, that our relatives are more important to us than others. 他们说血浓于水，亲属对我们来说比其他人更重要。
5. than从句省去部分谓语，保留主语和be,have或助动词
The white collar workers earn more than the blue workers do. 白领工人比蓝领工人挣得多。
这时 我们可以进行倒装，即将than后从句中的be,have或助动词移到该从句的前边
13) Hot objects emit do cold objects.
［A］ rays more than infrared(红外线)
［B］ rays are more infrared than
［C］ more than infrared rays
［D］ more infrared rays than
After all, big changes are relatively easier to make than are small ones. 相对来说，大变动比小变动毕竟容易些。
The fact is that some drug addicts are much better able to cure addiction in each other than are psychiatrists; some convicts can run better rehabilitation programs for convicts than do correctional officers; some patients in mental hospitals are better for each other than is the staff. 事实上，有些吸毒成瘾者与吸毒成瘾者之间戒瘾比精神病医生的作用还好；有些罪犯在改造其他罪犯方面比教改人员强；医院里的病人与病人之间的沟通比医务人员与病人间的沟通还强。
14) Last year the country had ［A］ fewer imports as ［B］ did the year before last ［C］ due to ［D］ the energy crisis.
6. than从句可以省去主语和部分谓语，保留宾语
Grandma gives more candies to her grandson than her granddaughter. 奶奶给孙子的糖比给孙女的多。(省去了she gives candies to)
7. than从句可以省去主语和谓语，保留状语
There are more books in this library than in that library. 这个图书馆的书比那个多。(省去了there are many books)
She is much better than yesterday. 她比昨天好多了。(省去了she was)
Signs of dishonesty in school, business, and government seem much more numerous in recent years than in the past. 近些年来在学校、商业和政府中欺诈的迹象比以前更多。
8. than从句可以省去主语，保留谓语部分
His speed of doing the work was much faster than had expected. 他干此事的速度远比想象的快。(省去了he或we)
9. 有时可以省去整个than从句
He is much healthier and happier. 她比以往任何时侯都健康幸福。(省去了than he was ever before)
10. 为了避免重复，我们经常用that代替不可数名词, those代替复数名词,one代替可数名词单数
15) Long Island， an ［A］ island that forms the ［B］ southeastern part of New York， has a ［C］ greater population than which ［D］ of forty瞭wo of thefifty states.
16) The grain of rye is longer ［A］ and slenderer ［B］ than ［C］ those of ［D］ wheat.
17) The activities of the international marketing researcher are frequently much broader than .
［A］ the domestic marketer has
［B］ the domestic marketer does
［C］ those of the domestic marketer
［D］ that which has the domestic marketer
七、隐含比较级
有时比较级并不一定出现than，这时通过上下文可喑示出，如：-Of the two oranges, which do you choose? -I like the larger one.这里的larger one是指前边提到的两个当中的较大的一个。而且有些形容词在表示比较的时候，跟“to”而不用“than”
1. prior to 较早的，较重要的
The task is prior to all others. 这项任务比其他所有的任务都重要。
I called on him prior to my departure. 动身前我去看了他一趟。
2. superior to优越，高于
In math he felt superior to John. 他觉得自己数学比约翰强。
They were resolved to rise superior to every obstacle. 他们决心战胜一切困难。
3. inferior to 下等的，次的
These apples are inferior in flavour to those. 这些苹果的味道不如那些。
4. senior to 年长的，地位高的；junior年幼的，地位低的，迟的
He is two years senior to me. 他比我大两岁。
Her appointment is junior to mine by six weeks. 她的任命比我迟六星期。
5. preferable to 更好的
Health without riches is preferable to riches without health.
贫穷但健康要比富有却多病更可取。
6. prefer…to 更倾向于…
I prefer this to that. 我喜欢这个而不喜欢那个。
八、最高级在特殊短语中的使用：在有下列短语的句子中，往往使用最高级
1. one of…
18 The grape is cultivated plants.
［A］ one of the oldest
［B］ the oldest one
［C］ one which the oldest
［D］ the one is the oldest of
2. of(among) all＋三者以上名词或代词
19) ， William Shakespeare is the most widely known.
［A］ With all writers in English
［B］ All writers in English
［C］ All of the writers in English
［D］ Of all writers in English
20) The crane is of the wading birds.
［A］ the tallest
［B］ the tallest that is
［C］ which is the tallest
［D］ which the tallest is
3. in the world(或群体名词)
21) The Appalachians Trail， extending ［A］ approximately 2，020 miles ［B］ from Maine to Georgia， is the longer ［C］ continuous ［D］ marked footpath in the world.
22) La Paz， Bolivia is the higher ［A］ capital city in ［B］ the western hemisphere and ［C］ the second瞙ighest ［D］ in the world.
九、其他有关比较的习惯表达法
1. “as ＋形容词(副词)＋as possible”结构，表示“最…，尽可能…”：“as quickly as possible”(尽量快)
23) The best way to control rats is by seeing that they have as .
［A］ possibly little nourishment
［B］ nourishment possibly little
［C］ little as possible nourishment
［D］ little nourishment as possible
2. “ sooner or later”是成语，表示“迟早、早晚”
24) Earlier ［A］ or later， all lakes are influenced ［B］ by eutrophication， a process in which lake sediment(沉积物) lowers the depth ［C］ of the water and drains(除去) oxygen from it ［D］ .
3. “would rather ＋动词原形＋than …”是惯用句型，表示“宁愿…而不愿…”，由于连词than 要求前后所比较的成分要一致
25) Alexander Graham Bell once told his family that he would rather be remembered as a teacher of the deaf ＃5]of the telephone.
［A］ than inventing
［B］ than as the inventor
［C］ the invention
［D］ as the inventor
十、most表示“非常”： 有时most并不表示“最……”，而是作副词表示“非常”之意。其实它是much的最高级，作形容词用是“大多数”之意，前边不加the。另外much与to构成介词词组，表示“在很大程度上使……”that也可以作副词用，表示“如此，那么”相当于so
26) Wool is characteristic on which to classify breeds of sheep.
［A］ most obviously
［B］ obvious the most
［C］ the most obvious
［D］ the most obvious that is
27) The Democratic party has controlled ［A］ the most ［B］ of the elected positions at ［C］ state and local levels in South Carolina since ［D］ the Reconstruction.
28) During ［A］ the seventeenth century the most ［B］ colonists were primarily concerned with ［C］ D)] economics ［D］ and defense.
十一、形容词与副词的修饰关系： 一般来说，形容词用来作表语(与系动词连用，注意taste, feel, become等词作系动词用时，它们后的表示应该是形容词，包括瞖d分词)或作定语修饰名词，而形容词不能修饰形容词包括睧D分词；但副词可以修饰形容词(包括睧D分词)，副词还可以修饰副词、动词或短语
29) Belgium, in the ［A］ 19th century, rapid ［B］ grew into ［C］ an industrial ［D］ country.
30) The Lost Colony in North Carolina mysterious ［A］ disappeared between ［B］ 1587 and 1590, when its ［C］ founder returned from a visit ［D］ to England.
十二、形容词与副词的位置
1. 当几个形容词共同修饰同一名词时，它们的先后顺序是：限定词→数词→描述性形容词→大小、长短、形状的形容词→色彩形容词→类属形容词→表材料形容词+被修饰的名词；或只记住限定词像a, the, my, their等词在最前边，其他词根据它们与被修饰名词关系的远近进行安排
31) Many flatworms have of eyes.
［A］ more pairs than one
［B］ more than one pair
［C］ one more pair than
［D］ one pair more than
32) Of the two houses the family prefers .
［A］ the most isolated one
［B］ the one isolated more
［C］ the more isolated one
［D］ the isolated one more
33) Freezing is at present one of the of preserving meats and vegatables.
［A］ most methods are important
［B］ methods most important
［C］ most important methods
［D］ most are important methods
2. 一般来说，单个副词修饰形容词时，副词放在形容词前；但enough修饰形容词时要放在形容词之后
good enough, mysterious enough
3. so修饰的是副词，而such修饰的是名词
34) The radio was of so ［A］ inferior quality that ［B］ I took it back ［C］ and asked for a better one ［D］ .
3. 形容词修饰名词时放在前边，但修饰复合不定代词(something, someone, somebody; anything, anyone, anybody; nothing, no瞣ne, nobody)时，则放在这些词之后
something important, anything possible
十三、关于hardly, rarely, scarcely与seldom的用法
hardly“刚刚，不完全”，表示程度：I hardly know him. “我几乎认不出他了”，表示还是能认出或者说“我刚刚能认出他”；hardly与any连用表示“几乎没有”，与ever连用表示“几乎从来不”； scarcely的意思与hardly更接近。rarely“不经常”，表示事物发生的频率：He rarely goes there. 他很少(不经常)去那里。seldom“很少，不经常”，它与rarely更接近。
十四、例题解析
1) D错。 改为than。
2) B对。本句的汉语意思是“照相机的镜头和眼睛的水晶体所起的作用相同”。
3) B对。本句的汉语意思是“消除通货膨涨会保证还的钱与借时的钱同值”。
4) B为正确答案。
5) C为正确答案。
6) D错。 改为warmer。
7) A为正确答案。
8) C为正确答案。
9) D为正确答案。
10) D为正确答案。
11) B错。 改为worse。
12) C错。 改为less。
13) D对。本句中的比较级为形容词more (much 的比较级)，被比较的两个事物为“hot objects”和“cold objects”，在所释放(emit)的红外线(infrared rays)的量上，前者多于后者。其中more修饰infrared rays，它们不能被分开，故只有D在词序上正确。空白后面为倒装语序，其中的do代替动词emit，本句空白后也可用正常语序，即“cold objects do”。
14) B错。 改为than。
15) D错。 改为that，代替population。
16) D错。 改为that。这里比较的“The grain”不是复数，不能用复数代词those。
17) C为正确答案。比较句中，连词than前后，即所比较的成分要一致，应该在同种事物间进行比较。本句所比较的是两种 activities ，故C正确，代词those 代替“the activities”。
18) A对。“one of the oldest…”表示“(历史)最长的栽种植物之一”，C和D均不合语法，而B选项中的one多余。
19) D为正确答案。
20) A为正确答案。
21) C错。只有在两者相比较时才使用比较级，而本句出现了状语in the world，明显表示不止两者相比，故应改用最高级 (the) longest 。
22) A错。 改为the highest。
23) D 为正确答案，“as little nourishment as possible ”意为“尽可能少的养料”。
24) A错。改为sooner。
25) B 为正确答案，两个短语“as a teacher of the deaf”和“ as the inventor of the telephone”相比。
26) C为正确答案。注意： 空档后的“characteristic”是名词而不是形容词，所以不能填A。
27) B错。 改为most。
28) B错。 改为most。
29) A错。改为rapidly。
30) A错。改为mysteriously。
31) B为正确答案。
32) C为正确答案。
33) C为正确答案。
34) A错。 改为such。